The present invention relates to vegetation cutting apparatus of the type disclosed in U.S. Pat. Nos. 3,826,068 and 3,859,776 issued to George C. Ballas and Thomas N. Geist. In general, this type of vegetation cutting apparatus comprises a rotatable head from which at least one length of flexible nonmetallic line extends. The line is supplied from a spool removably housed within the head, the line passing through an opening in the side of the head whereby as the latter rotates, the line extending therefrom engages and cuts vegetation.
An important consideration in effectively cutting vegetation is to maintain the proper length of line extending from the housing. During operation, the line is subjected to wear and damage. Accordingly, additional line must periodically be drawn from the spool.
In the arrangement disclosed in U.S. Pat. No. 3,859,776, the spool is locked with respect to the rotatable head. Therefore, in order to draw line from the spool, it is necessary either to (1) detach the spool from the head, release the desired length of line and then resecure the spool to the head; or (2) with the spool locked in place, grasp the free end of the line and pull additional line past the flange of the spool. These procedures are inconvenient and often wasteful.
In the arrangement of U.S. Pat. No. 3,826,068, line length can be adjusted without removing the spool, but this requires complex mechanical structure for dispensing the line in incremental lengths. Such an arrangement, as in the case of U.S. Pat. No. 3,859,776, requires that the cutting apparatus be shut off when the line length is to be adjusted.
In U.S. Pat. No. 4,007,525, issued to Gordon Francis Utter on Feb. 15, 1977, there is disclosed an improved, inexpensive arrangement which permits the proper length of cutting line to be dispensed from the spool in a simpler and more economic way than in U.S. Pat. Nos. 3,826,068 and 3,859,776. However, with this arrangement, it is also necessary for the cutting apparatus to be shut off when the length of line is to be adjusted.